Theoretical Investigation On Dissociation Mechanism Of The Ionized Cyclohexanone In Excited States

It is important to know the structure ,stability and vibrational spectra of excited state of ionized molecule in order to comprehend the multiphoton ionization/dissociation processes of molecules in ultrashort pulse duration laser field. Our theoretical study aims to analyze ionization and dissociation mechanism of cylcohexanone in the excited states and gives out a result with proved and directed significance for the corresponding experiment investigating works.The calculation of the excited state of ions and the analysis of dissociation according to the vibration patterns has been made by using the CIS(Configuration Interaction with Single Substitute) method, adopting 6-31+G(d) basis set to calculate the frequency of excited state of cylcohexanone ion molecule. We have investigated the different vibration patterns of C-C bond and C-H bond under different excited states with imaginary frequency. Five dissociation channels have been obtained. The possible dissociation fragments in the excited state are generally C4H5O+,,C3H3O+,C2H2O+,C3H6+,C3H3+ etc. Every possible sort of stable structure and vibrational frequency of various fragments are calculated using the method of B3LYP/6-31+G (d, p). The dissociation channels of ionized cyclohexanone in the excited states are given as follows:...